The invention relates to a device for the storage of electromagnetic control signals on at least one selected longitudinal section of magnetic strip material such as a magnetic tape, a motion picture film equipped with magnetic sound tracks, and the like, the beginning and/or the end of each longitudinal section being defined by a mark and a magnetic head operatively associated with the magnetic strip material and connected to means for the amplification of recording and reproduction.
In addition, the invention also relates to a sound film projector having a device as described above, for the production of motion picture films, preferably narrow films, provided with at least two magnetic sound tracks, at least one sound track being associated with a magnetic head connected with means for the amplification of recording and reproduction, and arranged for the storage of acoustic signals such as commentary, accompanying music, etc., while the other magnetic sound track of the motion picture film is arranged for the storage of the control signals.
A sound film projector for narrow film is well known and has, besides the customary recording key, an erasing key through the actuation of which information already stored on the magnetic tape track of the film may be erased and new information may be stored. By means of this erasing key, it is possible to erase passages of any desired length. The provision of such a device on a sound projector brings about a simplification of operation when compared to the switches previously used. However, when it is desired to erase a sequence completely and apply new commentary or new accompanying music and/or sounds to that sequence of pictures, it would be necessary to identify the beginning of the sequence with precision, and to immediately actuate the erasing key. Similarly, the erasing key would have to be released exactly at the end of the sequence. But, in practice, this can hardly be achieved and/or may not be expected from the operator. Particularly, in the case of "life-sound" recordings, imperfect sound recordings frequently occur and must be replaced later by recordings of better quality. In most cases, a complete sequence is of inferior quality so that the amateur is compelled to erase the acoustic information stored at the time of the recording from the beginning of the sequence to its end.